This invention is in the field of catheter connectors wherein a catheter connector is coupled to the proximal end of a catheter.
Many catheters, including but not limited to epidural catheters, need to be coupled to catheter connectors situated near the insertion site on a patient. Such a connector secures the proximal end of a catheter from both axial and transverse movement, and often includes one or more fluid couplings for communicating fluids into or out of the catheter.
It is important for the surgeon and other medical personnel to be able to make this coupling of the connector with the proximal end of the catheter quickly, easily and securely. Also it is desirable for the connector to be relatively inexpensive, if possible, since these are often disposable, non-reusable devices which adds to the already expensive cost of invasive medical procedures.
The objects of coupling securely, quickly, easily and economically often call for design features that are in conflict with each other. With regard to a secure coupling that bars axial or transverse movement of the catheter, prior art devices usually apply inward radial compression to one or more outer surface areas of the catheter; however, excessive pressure will collapse the soft tubular catheter and at least partially close the inner fluid passageway, and insufficient pressure will not hold the catheter securely.
This coupling is necessarily a manual event by the user's hands and fingers. Thus, even if the user were able to apply the ideal amount of compressive force on a catheter on one occurrence, such would not necessarily happen on the next occurrence. It is most difficult for users of these devices to always select the correct gripping force in the many various medical procedure circumstances and in the extremely limited time to make the decision.
In addition to the above-described objective of securely engaging the catheter, the coupling procedure needs to be easy and quick. There is little time for a doctor or nurse to adjust and/or study the device.
Numerous prior art devices apply inward radial force on the catheter by simply pressing inward with a rigid element of the connector. Such force is applied to one specific outer area, or is applied circumferentially around the catheter outer wall by a compressible collar surrounding the catheter. In the latter case the compressible collar is situated coaxially within the bores of a pair of mating sleeves which are threadedly engaged. When these sleeves are screwed together, they apply axial force to the collar that is then deformed radially inward against the catheter. Such rotation of one sleeve relative to another necessitates use of two hands by the operator. Such two-handed operation requires time and coordination, and as discussed above, the user is unlikely to be able to apply the same force every time. Of the many prior art catheter connector devices which use threaded elements to achieve deformation of a plug through which a catheter extends, U.S. Pat. No. 5,464,400 to Collins illustrates male and female coupling elements which axially compress a hexagonal slug. As with other threaded couplings, two hands are required; there is no contemplation of operating this device with one hand or of designing any device for such operation.
Another typical prior art connector structure having telescoping sleeves threaded for rotation by a two-handed operation that compresses a collar 15 is seen in U.S. Pat. No. 6,260,890 to Mason.
U.S. Pat. No. 6,228,059 to Hoffman shows a still different locking means, for a trocar, where a locking element 58, as seen in FIGS. 2 and 3, bears down at one area on the side wall of instrument 34. U.S. Pat. No. 6,096,024 to Graves et al. shows a pivoting latch which engages the side wall of a needle cannula. U.S. Pat. No. 5,931,671 to Hoffman discloses a pair of compression elements that move transversely inward to releasably engage and hold a central tube.
This long-practiced concept of applying lateral force directly to a central tube or element is seen most clearly in U.S. Pat. No. 5,725,504 to Collins, where a simple cam lever 28 pivots to engage and deflect wall 27 against hub 12.
The prior art devices described above demonstrate that the long-established modes to secure a central shaft, whether it is a rigid or soft tube or shaft, are either: (a) to use a pivot lever to apply an inward radial force directly onto the side wall of the central shaft, or (b) to use a pair of threaded sleeves, rotatable by a two-handed operation, to apply an axial force to a collar which in turn applies an inward radial force to a central tube.
The more extensive use of catheters and the more intricate surgical procedures has led applicants to an approach which utilizes some known elements and combines them in a new and most useful way. The present invention seeks to overcome all of the above-described faults and disadvantages in prior art catheter connectors with a new device that allows coupling to be secure, quick, easy, uniformly applied and achievable with a single hand.